The invention relates to an arrangement in an anesthesia apparatus, the anesthesia apparatus comprising a vaporizer and a dosing device for anesthetic and the arrangement comprising a filling device in connection with the vaporizer and an anesthetic bottle that fits the filling device, the filling device being provided with a valve device, which is arranged to open and close as needed.
Anesthesia apparatuses are used during surgery in operating theaters in hospitals. The most essential components of an anesthesia apparatus are a vaporizer and a dosing device for anesthetic. The components can be integrated or separate units, as in cassette-type structures. The main components of a vaporizer are a liquid container including a vapor generator, and a filling device. The filling device serves to supply the anesthetic to or remove it from the liquid container. Anesthetic agents, i.e. anesthetic liquids, are stored in dispensing cylinders, such as transport and storage containers, also referred to as bottles. Each anesthetic has a dedicated, profile-coded bottle opening, so a storage bottle can only be connected to a filling device suitable for a respective anesthetic, either directly or through a profile-coded adapter.
There are various anesthetic liquids, of which desflurane can be mentioned here. A special characteristic of desflurane in comparison with other anesthetic liquids is that desflurane boils at room temperature, whereby the pressure inside the bottle rises as the temperature rises. For this reasons the opening of a desflurane anesthetic bottle is provided with a profile-coded valve device, the normal position of which is a xe2x80x9cclosedxe2x80x9d position. In addition to the bottle and the valve, the structure also comprises a closing lid, which is screwed on top of the valve to ensure the prevention of leakage during a longer period of storage.
The valve construction of a desflurane bottle is of such type that the bottle seals with the filling part of the vaporizer on the outer edge of the valve and the valve is activated to open and close from the bottom of the inner recess of the front surface. Due to the construction, there is an interspace between the valve seal and the filling part of the vaporizer where is always left a small amount of anesthetic and gaseous anesthetic, which are released in the ambient atmosphere towards the end of the filling situation at a pressure determined for instance by temperature differences of the bottle and the filling device. It is particularly important that the capacity of the above mentioned interspace is as small as possible to ensure that the amount of hazardous spatters of anesthetic sprinkled in the surroundings or, in the worst case, on the operator""s hands and in his/her face remains small.
In an attempt to minimize the amount of anesthetic remaining in said interspace, in prior art arrangements the tilt angle of the bottle has been set at 45xc2x0 from a horizontal level. The tilt angle can be used to influence the flow rate of the anesthetic and the amount of waste anesthetic, the amount of anesthetic remaining in the interspace being determined by the top threshold of the bottle opening and the tilt angle. The flow rate must also be sufficiently high so as to allow a maximum amount of anesthetic to flow during a rapid emptying operation. On the other hand, a large tilt angle can be harmful since a disadvantageous angle causes waste anesthetic to be spattered on the operator""s hands. It is thus possible to mathematically calculate the tilt angle that will minimize the amount of waste anesthetic, but an optimal tilt angle consists of various factors.
A problem in prior art solutions has been that they have not provided for a controlled management of the amount of waste anesthetic and gaseous anesthetic remaining in the interspace to ensure that it does not provide a risk to the operator.
An object of the invention is to provide an arrangement that will allow the drawbacks in the prior art to be eliminated. This is achieved by means of the arrangement of the invention, characterized in that the arrangement comprises a discharge space, which is connected to an interspace formed between the anesthetic bottle and the valve device located in the filling device when the anesthetic bottle is being pulled outward, and a closing member, which, as a result of the anesthetic bottle being pulled outward, is arranged to open a flow connection between the interspace and the discharge space before the connection between the anesthetic bottle and the filling device opens.
An advantage of the arrangement of the invention is, above all, that anesthetic and gaseous anesthetic remaining in the interspace can be directed to a desired place in a fully controlled manner, the apparatus thus offering better properties in use than prior art devices. A further advantage of the invention is its simplicity, due to which the invention is advantageous to implement and to use.